The invention concerns a device for positioning a welding electrode in an orbital tube-welding apparatus. Such apparatus are used to weld hollow objects to each other, such as a tube with a conical tube.
FIG. 1 illustrates a tube 3 which is to be welded to a conical structure 6, which is hollow, and will be termed conic 6 herein. The tube 3 fits into a recess 9, and is held concentric to the conic 6 by an annular flange 12. FIG. 2 shows the tube 3 placed in position for welding. Dashed ellipse 15 represents a region which is shown in cross-sectional view in FIG. 3. Tube 3 is shown, as are annular flange 12 and conic 6.
The Inventor has identified a difficulty which occurs in welding the structures of FIG. 2 together, and has advanced a solution.
In one form of the invention, a laser is affixed to a welding electrode, and projects a laser beam in a predetermined spatial relationship with the electrode. A human operator positions the laser beam on a target, which has a predetermined spatial relationship with a spot to be welded. The electrode thereby becomes positioned at a predetermined spatial position with respect to the spot.